There is a need to keep pharmaceutical, health care and other products at a constant and regulated moisture level when they are stored in a container assembly. The packaging industry has been challenged to provide a package that is clean, a barrier to moisture vapor, child resistant and now having a means to keep the product fresh by maintaining a relatively consistent humidity within the container assembly. It is the freshness that has been the challenge as the packaging industry has already met the other requirements without much difficulty.
In order to keep contents fresh, controlling relative humidity at a specified level is preferred. The desired humidity or predetermined humidity to maintain freshness is variable in that different products prefer maintenance at different relative humidities. For example, some products are able to maintain freshness when kept dry or at zero or relatively close to zero relative humidity and other products maintain freshness when maintained at a relatively high level of humidity. The preferred invention addresses the maintenance of a predetermined relative humidity in a container assembly to maintain the freshness of a product held in the container assembly, which may be a pharmaceutical product, a health care product, a food product or nearly any product that may benefit from storage in a predetermined humidity environment.
For many packaged products, including packaged consumer products, it is beneficial to maintain a particular moisture content within the package containing the product. In some cases, the space within a product package that is not taken up by the product itself. Some devices are configured to help maintain a consistent relative humidity (“RH”) of the space within the product package that is not taken up by the product itself. The RH may be maintained at a level or range deemed optimum for the particular packaged product. It is understood to those skilled in the art that the percent RH (“% RH”) in the package will result in a percent by weight product moisture content, but that the % RH in the space not taken up by the product and the product percent moisture by weight are different values that differ based on the characteristics of the product and its propensity to absorb moisture from the surrounding atmosphere. Many products may be consumed or utilized by a consumer over a period of time, and maintaining a consistent RH may help preserve the life, integrity, freshness, flavor, or other features of the product.
One commonly used device for controlling RH in packaged products is a loose pouch containing a salt solution. As disclosed in U.S. Pat. No. 5,936,178, entitled Humidity Control Device, and filed Jun. 10, 1997, the contents of which are hereby incorporated by reference in their entirety, the RH of closed environments can be stabilized by the use of humidity control systems comprised of moisture permeable pouches containing specific salt solutions. However, this method of providing the humidity control feature through pouches that are loose in the product package creates inconvenience, potential contamination and perception disadvantages, such that manufacturers or consumers refuse to, or are prevented from, using this approach. For example, consumer confusion may arise as to whether the packet is something other than a humidity control device. In some cases, loose packets may be intentionally or mistakenly discarded by consumers when opening and closing the product packaging, particularly with repeated opening and closing of the packaging over time and opening or closing by consumers who are not familiar with the purpose of the pouch. Such approaches may also require specialized materials.
Dehumidification pouches have been utilized inside container assemblies to maintain the moisture level through absorbing the excess moisture. These pouches are stored in the container and intermingled with the product, such as pharmaceuticals or foods, in the container, resulting in surface contact between the pharmaceuticals, foods or other products and the pouches. Such intermingling and direct contact between the pouches and products are generally undesirable and consumers prefer not to have the pouches intermingled with the product such that the pouches fall out of the container when the consumer is dispensing products for use and the pouches come into direct contact with the stored products during storage and transport. There is no generally known system or method for adding and removing moisture to the contents of the container during typical use and appropriately isolating the RH control material.
The subject of this preferred invention is directed to packaging that has made it possible for a container to incorporate addition and removal of moisture from the container assembly during normal use, without including the pouch or humidity control material intermingled with the contents of or product in the container. The preferred invention allows for the preservation of substances and objects sensitive to humidity, such as particular foods, pharmaceuticals, and herbs. Particularly, the preferred invention relates to devices for controlling the relative humidity within consumer product packages, and methods for making such devices, wherein the humidity control material is contained in a compartment associated with the product packaging.